The core of daily maintenance for the negative pressure weighing chamber is as follows: daily cleaning + parameter inspection, weekly deep cleaning and seal check, monthly filter and duct maintenance, annual leak detection and calibration. The entire process follows GMP to ensure stable negative pressure, compliant airflow, and no cross-contamination.
\n1. Daily Maintenance (per shift \/ per day)
\n1. Before startup check
\nNegative pressure value: The differential pressure gauge shows **-15 to -30 Pa**, stable without fluctuations.
\nWorking surface wind speed: 0.35 to 0.45 m\/s, no turbulence.
\nFunction status: Fan, lighting, alarm are normal, no abnormal noise, no air leakage.
\nAppearance cleanliness: Inner walls, tabletop, return air vents, operation ports have no dust or residual materials.
\n2. Cleaning and disinfection (must be done after operation)
\nPower off protection: Turn off power and ventilation, wear gloves, protective clothing, and mask.
\nRemove residues: Use dust-free tools to remove residual materials on the tabletop to avoid touching the materials.
\nSurface wiping: Dip a dust-free cloth in purified water \/ 75% ethanol, wipe the tabletop, side walls, and door body from top to bottom, from inside to outside in a single direction; use cotton swabs to clean the gaps.
\nDisinfection: Secondary wipe with 75% ethanol or 3% hydrogen peroxide, leave it to stand for 10 to 15 minutes.
\nDrying: Let it air dry or dry with a dust-free cloth, do not allow water to enter the electrical components and filters.
\nProhibited: Do not use strong acids or strong alkalis; do not wash HEPA with water; do not stack materials at the return air vent.
\n3. Shutdown and record
\nSelf-cleaning for 10 to 15 minutes after operation before shutting down.
\nFill in operation, differential pressure, wind speed, cleaning records to ensure traceability.
\n2. Weekly Maintenance
\nPrimary \/ return air filter: Remove for washing (soft brush + neutral cleaner), air-dry, avoid direct sunlight, reinstall and seal.
\nSeal check: No cracks or air leakage in door frames, inspection ports, and glass gaskets.
\nParameter calibration: Calibrate and record the differential pressure and wind speed sensors.
\nOverall disinfection: Ozone \/ ultraviolet (unattended) + surface wiping; ultraviolet prohibited for people \/ materials.
\n3. Monthly Maintenance
\nMedium-efficiency filter: Check for dust accumulation, replace when differential pressure exceeds threshold.
\nFan and duct: Clean the dust accumulation in the fan chamber, inner walls, and duct, prevent secondary dusting.
\nCircuit inspection: No looseness or overheating of wiring, switches, and frequency converters.
\nGloves (Grade A): Clean, leak check, replace if damaged.
\n4. Quarterly \/ Annual Maintenance
\nQuarterly: Replace primary efficiency filter; check HEPA differential pressure (final resistance exceeds 500 Pa, replace).
\nAnnual: HEPA leak detection; fan \/ control system calibration; comprehensive seal and airflow test.
\n5. Filter Replacement Cycle (Reference)
\nPrimary efficiency: 1 to 3 months (replace when clogged).
\nMedium efficiency: 3 to 6 months (replace when differential pressure increases).
\nHEPA: 12 to 24 months (replace when differential pressure exceeds 500 Pa or leak detection fails).
\n6. Safety and Compliance Key Points
\nPower off for 10 minutes before operation to prevent electric shock.
\nUse GMP-approved cleaning agents \/ disinfectants, compatible materials.
\nProhibit use of fiber cloths; tools are dedicated and divided.
\nEstablish maintenance ledger: date, project, parameters, personnel, abnormal handling.
\n7. Common Abnormal Handling
\nInsufficient negative pressure (> -15 Pa): Check for door \/ seal leakage; primary \/ medium-efficiency blockage; abnormal fan speed.<\/p>","protected":false},"excerpt":{"rendered":"
The core of daily maintenance for the negative pressure weighing chamber is as follows: daily cleaning + parameter inspection, weekly deep cleaning and seal check, monthly filter and duct maintenance, annual leak detection and calibration. The entire process follows GMP to ensure stable negative pressure, compliant airflow, and no cross-contamination. 1. Daily Maintenance (per shift […]<\/p>","protected":false},"author":12,"featured_media":5335,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[92],"tags":[],"class_list":["post-5504","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/5504","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/comments?post=5504"}],"version-history":[{"count":1,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/5504\/revisions"}],"predecessor-version":[{"id":5505,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/5504\/revisions\/5505"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/media\/5335"}],"wp:attachment":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/media?parent=5504"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/categories?post=5504"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/tags?post=5504"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}